Mr Mears said: "I have no doubt that the company will go from strength to strength in the coming years, and look forward to following its continued progress."

Since taking over as artistic director in 2010, Mr Mears has helped to give Northern Ireland Opera a more prominent presence on the international stage.

In 2012, his version of Benjamin Britten's Noye's Fludde, which was originally produced at Belfast Zoo, was shown at the Beijing and Shanghai Festivals.

The company's 2013 version of Britten's The Turn of the Screw won praise from critics in its appearances at the Buxton Festival in Derbyshire and at the Novaya Opera in Moscow.

Mr Mears has also championed the work of Northern Irish composers.

Roisin McDonough, Chief Executive of the Arts Council of Northern Ireland, said: "The Arts Council is delighted at Oliver's appointment and we wish him the very best for what will no doubt be a bright future.

"The success of Northern Ireland Opera over the past six years shows just what we can achieve for the arts in Northern Ireland, with a combination of funding, talent and ambition.

"The international quality and scope of Northern Ireland Opera's work is testament to the potential of the whole sector here."

Mr Mears was the founding artistic director of Northern Ireland Opera and has been praised for his focus on local talent, as well as his determination to make opera more accessible to all.

He has worked to engage with local councils and schools which otherwise would be unlikely to have the chance to experience the art form.

Under his leadership, Northern Ireland Opera began the Young Artists Programme, designed to support up-and-coming performers early in their career.

He has also supported the annual Festival of Voice in Glenarm, which offers young Irish singers the chance to work with established opera stars.

Mr Mears still has time to oversee two final pieces with Northern Ireland Opera - a new production of Don Giovanni at the Grand Opera House in Belfast and the Irish premiere of Powder Her Face at the Lyric Theatre in January.

Roy Bailie, chairman of the Northern Ireland Opera board, said: "We are very sad to see Oliver's departure, it has been wonderful to see the dedication, energy and imagination which he and his brilliant team have brought to the task of making the creation and work of a national company a success.

"On the other hand, we are thrilled that he will be moving to such a prestigious position at the Royal Opera House.

"The task now begins to find a successor who will continue the work that we have achieved so far."